Marsh marigolds are not marigolds at all—they are members of the buttercup family.
They are native to temperate regions
in Europe, Russia, Iceland, and North America. This plant is sometimes called cowslip,
but another plant, Primula veris, is the proper owner of this name.

Identification: These plants are found in marshes,
fens, and bogs. They are up to 31" (80 cm) tall. Glossy rounded or kidney-shaped leaves are up to 8" (20 cm)
across. Bright shiny yellow flowers often have five petals, but may have between four and nine.
Each flower is about 1-1½" (2.5-3.8 cm) across. Stems are thick and hollow.

Edibility: Members of the buttercup family are poisonous ,
and marsh marigolds are no exception. However, young leaves (no stalks), harvested while the plant is still
flowering, may be cooked in several changes of boiling water, producing an “excellent”[1] result.

It used to seem unlikely (okay, preposterous) to me that someone would carefully harvest portions of a poisonous
plant, and boil them in several changes of water, just to produce a side dish.
But this isn’t some long-extinct cultural practice. In
Gathering Moss: A Natural and Cultural History of Mosses, Robin Wall Kimmerer gathers marsh
marigolds for a dinner treat with almost the same sense of routine that I reserve for morning coffee.
Ellen Zachos, author of several books on house plants, makes delicious preserves and wines
from a wide variety of plants, both wild and cultivated.

These days we don’t very often need such plants for survival, but experiencing a mushroom that
tastes like lobster, or a glass of elderberry champagne, or the unique flavor of wild asparagus is an adventure.
Why do we sample so little of nature’s bounty?